I read the following
World-recognized decompression physiologist and cave explorer David Doolette explains the new evidence-based findings on “deep stops,” and shares how and why he sets his own gradient factors. His recommendations may give you pause to stop (shallower).
gue.com
mentioning quote "
A large study conducted by the U.S. Navy compared the incidence of DCS in air decompression schedules for 30 minutes bottom time at 170 fsw bottom for a gas content algorithm with the first stop at 40 fsw (shallow stops) or a bubble algorithm with the first stop at 70 fsw (deep stops). The shallow stops schedule resulted in 3 DCS in 192 man-dives and the deep stops schedule resulted in 11 DCS in 198 man-dives.
"
Some questions did arise ...
Is 198 divers really that representative? large study?
navy divers vs regular divers?
To deep stop or not to deep stop?
Let's take Buhlmann ZH-L16B
dive 40 minutes at 40 meters
EAN28, DECO mixes 50 and 100
decoplanner 4.6.3 shows
GF 70/80
@12 01 min 50%
@09 05 mins 50%
@06 14 mins 100%
GF 20/80
@21 01 min 50%
@18 01 min 50%
@15 01 min 50%
@12 02 mins 50%
@09 05 mins 50%
@06 12 mins 100%